Molecular Crystals and Liquid Crystals · 2003 · 41 citations · 5 references
Optical MaterialsEngineeringLiquid Crystalline ElastomerFiber OpticsAbstract DispersionsPolymersPolymer MaterialPolymer TechnologyOptical PropertiesPolymer ProcessingOptical SystemsOptical CommunicationPdlc PerformancePolymer ChemistryPhotonic MaterialsPolymer EngineeringOptical-fiber Variable AttenuatorOptical SensorsPolymer SciencePolymer PropertyOptoelectronicsLiquid Crystals
Abstract Dispersions of liquid crystals in polymeric matrices (PDLC) are used as light Variable Optical Attenuators (VOAs). Electronically controllable VOAs play a crucial role for channel power equalizers in WDM systems. This article describes the theoretical model optimizing PDLC performance and the fabrication process utilizing the polymerization-induced phase separation (PIPS) method, and presents the optical attenuation (OA) and polarization dependence loss (PDL) characteristics versus fabrication conditions. Fabricated VOAs have a large attenuation range (10–30 dB) and low insertion loss (IL) at a 1.55 µm wavelength (0.5 dB). Depending on the fabrication parameters, the OA, IL, and PDL are optimized. This device needs an applied voltage V90 of 10 to 70 Vrms for 10–100 µm PDLC thickness. The flatness of the optical characteristics of this device has also been measured in the C+L band. Keywords: liquid crystal nematicelectro-optic propertiespolymerizationPDLCVOA
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